Alert archive / Arizona / Flash Flood Warnings in 2025

Flash Flood Warning 36, NWS Phoenix, AZ

September 4, 2025La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 4, 2025, 4:26 PM MST for La Paz County, Arizona. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 4, 2025, 4:26 PM MST (23:26 UTC)
Expired: Sep 4, 2025, 8:30 PM MST
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 151 km from the middle of the area, began a volume at 23:26 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Yuma Prvg Ground, AZ (K1Y7), launched 12:00Z, 11.4 hours before the alert went out and 142 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3019 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1052 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -33 m²/s²
0-3 km storm-relative helicity: 15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Sep 4, 3:11 PM MST, 1 hour 15 minutes earlier.

Area forecast discussion, Sep 4, 3:11 PM MST, 1 hour 15 minutes before

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In the hours before

Special weather statement, Sep 4, 1:15 PM MST, 3 hours 11 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
115 PM MST Thu Sep 4 2025

AZZ530-531-533-042100-
Kofa AZ-Parker Valley AZ-Central La Paz AZ-
115 PM MST Thu Sep 4 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LA PAZ AND NORTH
CENTRAL YUMA COUNTIES THROUGH 200 PM MST...

At 115 PM MST, Doppler radar was tracking a strong thunderstorm 12
miles east of Yuma Proving Ground, or 19 miles northeast of Martinez
Lake, moving southeast at 10 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Kofa Wildlife Refuge, Palm Canyon, and Ehrenberg.

This includes the following highways...
AZ Interstate 10 near mile marker 4.
AZ Route 95 between mile markers 63 and 97.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 3342 11460 3362 11447 3345 11377 3297 11421
TIME...MOT...LOC 2015Z 302DEG 7KT 3313 11419

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

KB

Special weather statement, Sep 4, 3:04 PM MST, 1 hour 22 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
304 PM MST Thu Sep 4 2025

AZZ530-531-CAZ564-569-570-042245-
Kofa AZ-Parker Valley AZ-Chuckwalla Mountains CA-
Palo Verde Valley CA-Chuckwalla Valley CA-
304 PM MST Thu Sep 4 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LA PAZ...
NORTHEASTERN IMPERIAL AND RIVERSIDE COUNTIES THROUGH 345 PM MST/345
PM PDT/...

At 303 PM MST/303 PM PDT/, Doppler radar was tracking a strong
thunderstorm 13 miles southwest of Palo Verde, or 35 miles northwest
of Martinez Lake, moving southeast at 10 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Cibola and Palo Verde.

This includes CA Route 78 between mile markers 55 and 80.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3327 11443 3302 11473 3336 11533 3359 11503
TIME...MOT...LOC 2203Z 316DEG 7KT 3332 11492

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

KB

Special weather statement, Sep 4, 3:41 PM MST, 45 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
341 PM PDT Thu Sep 4 2025

CAZ564-565-569-042330-
Chuckwalla Mountains CA-Imperial County Southeast CA-
Palo Verde Valley CA-
341 PM PDT Thu Sep 4 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN IMPERIAL AND
RIVERSIDE COUNTIES THROUGH 430 PM PDT...

At 341 PM PDT, Doppler radar was tracking a strong thunderstorm 21
miles southwest of Palo Verde, or 33 miles southeast of Desert
Center, moving south at 10 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

This storm will remain over mainly rural areas of northeastern
Imperial and Riverside Counties.

This includes CA Route 78 between mile markers 58 and 69.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3333 11541 3351 11503 3324 11471 3303 11510
TIME...MOT...LOC 2241Z 003DEG 11KT 3331 11507

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

KB

Special weather statement, Sep 4, 3:50 PM MST, 36 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
350 PM MST Thu Sep 4 2025

AZZ538-539-559-042330-
Sonoran Desert Natl Monument AZ-Gila Bend AZ-Tonopah Desert AZ-
350 PM MST Thu Sep 4 2025

...STRONG THUNDERSTORMS WILL IMPACT MARICOPA COUNTY THROUGH 430 PM
MST...

At 349 PM MST, Doppler radar was tracking a cluster of strong
thunderstorms 10 miles east of Sentinel, or 18 miles west of Gila
Bend, moving north at 25 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Gila Bend, Sentinel, Cotton Center, and Painted Rock Dam.

This includes the following highways...
AZ Interstate 8 between mile markers 81 and 113.
AZ Route 85 between mile markers 12 and 23, and between mile markers
133 and 138.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3254 11321 3279 11333 3303 11333 3328 11300
      3319 11260 3291 11278 3264 11283
TIME...MOT...LOC 2249Z 168DEG 22KT 3292 11305

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

MS

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 3, 5:34 PM MST	Dust Storm Advisory	PSR	Pinal	86 min
Sep 3, 5:42 PM MST	Special Weather Statement	PSR	La Paz	48 min
Sep 3, 6:15 PM MST	Special Weather Statement	PSR	La Paz	45 min
Sep 3, 6:52 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	53 min
Sep 3, 7:01 PM MST	Severe Thunderstorm Warning	PSR	Pinal	29 min
Sep 3, 7:08 PM MST	Severe Thunderstorm Warning	PSR	Yuma	37 min
Sep 3, 7:43 PM MST	Severe Thunderstorm Warning	PSR	Pinal	47 min
Sep 3, 8:08 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	52 min
Sep 3, 8:14 PM MST	Dust Storm Warning	PSR	Maricopa, Pinal	46 min
Sep 3, 8:39 PM MST	Dust Storm Advisory	PSR	Maricopa	66 min
Sep 3, 8:40 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	35 min
Sep 3, 8:52 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	53 min
Sep 3, 8:54 PM MST	Flash Flood Warning	PSR	Maricopa	111 min
Sep 3, 8:59 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	46 min
Sep 3, 9:07 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	53 min
Sep 3, 9:18 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	3 hr
Sep 3, 9:20 PM MST	Severe Thunderstorm Warning	PSR	Pinal	25 min
Sep 3, 9:25 PM MST	Special Weather Statement	PSR		50 min
Sep 3, 9:48 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Sep 3, 10:53 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Sep 3, 11:26 PM MST	Areal Flood Advisory	PSR	Maricopa	2 hr
Sep 4, 12:11 AM MST	Areal Flood Warning	PSR	Maricopa	3 hr
Sep 4, 12:20 AM MST	Special Weather Statement	PSR	Maricopa	40 min
Sep 4, 1:01 AM MST	Areal Flood Advisory	PSR	Maricopa	119 min
Sep 4, 2:49 AM MST	Areal Flood Advisory	PSR	Maricopa	116 min
Sep 4, 1:15 PM MST	Special Weather Statement	PSR	La Paz	45 min
Sep 4, 1:35 PM MST	Areal Flood Advisory	PSR	La Paz, Yuma	9 min
Sep 4, 1:44 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	3 hr
Sep 4, 2:10 PM MST	Severe Thunderstorm Warning	PSR	La Paz	50 min
Sep 4, 2:21 PM MST	Areal Flood Advisory	PSR	La Paz	12 min
Sep 4, 2:31 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	3 hr
Sep 4, 2:44 PM MST	Dust Storm Advisory	PSR	Pinal	61 min
Sep 4, 2:48 PM MST	Severe Thunderstorm Warning	PSR	La Paz	42 min
Sep 4, 3:29 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	46 min
Sep 4, 3:50 PM MST	Special Weather Statement	PSR		40 min
Sep 4, 4:13 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	47 min
Sep 4, 4:23 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Sep 4, 3:04 PM MST	Special Weather Statement	PSR	Imperial	41 min
Sep 4, 3:25 PM MST	Flash Flood Warning Considerable damage threat	PSR	Imperial, Riverside	4 hr
Sep 4, 3:41 PM MST	Special Weather Statement	PSR	Imperial	49 min
Sep 4, 4:37 PM MST	Special Weather Statement	PSR	Imperial	38 min

Nearby

Flash Flood Warnings in Arizona, 2025 Every flash flood warning in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.